Hi. I'm planning to start a new character and playthrough the entire game (with the exception of the Dragonborn main quest) and leave Dawnguard until the end so I have something new to look forward to. But I don't want to be too high a level and it not be fun. So what level do you think would be too late for it to be challenging?

Thanks.

Well technically the game is the absolute easiest at lower levels. The game gets the most challenging once you near the peak of the scaling system, around 40-60. At level 58 is when some of the toughest enemies in the game like Forsworn Briarhearts stop scaling for example.

After level 60-ish is when enemies have stopped scaling in general and you're just gaining power in comparison. However in general the game is way way easier at lower levels, that is to say before level 40, than higher levels.

If you want the most challenge it's hard to say at what level you should takle it because we don't have the information on the scaling of the enemies in Dawnguard because it's not out on PC yet, but if it follows the scaling pattern of vanilla Skyrim I'd guess around late 40s to late 50s.

Of course you could also just turn up the difficulty setting of the game if you want it to be more challenging. I have to say though, personally I'd recommend you to just play Dawnguard whenever you feel like it, tends to work out better from my personal experience. Not that's it's any of my business to tell you what to do.

I did on Master at level 59-60 and it was pretty challenging. Even using a greatsword that deals 490 damage some enemies kicked my ass.

I did it on Expert at Level 71 and the enemies are still challenging- especially vampire mages who tend to spam frost and shock spells at you, having the effect of slowing you down and killing your magic; and bear in mind that this is even using my character which has >700 armour rating and >200 weapon damage. So, higher levels are still a good challenge when playing on higher difficulties.

Thats great, I can leave it until the end. Thank you.

I am a level 81 and it was a cake walk. I just equipped my master destruction spells, and everyone was either dead or half way there. But it being to easy also made it boring for me.

Exactly.

Totally dependant on your character type, how you spec, how much upgrading you do to your weapons, ect. Level doesn't have as much to do with it as what you do with your character. Even a high level character can be fairly weak if you don't take certain aspects of the game, such as smithing, enchanting, and alchemy, to their limits or choose to not use them at all.